Abstract
The rate of dissolution of sintered carbonate apatites was estimated in 10mM acetic acid solutions at 37℃ at a constant pH of 5.0.When compared at the same sintering temperature, the rate of dissolution increased with increased concentrations of carbonate initially present, indicating that the presence of carbonate plays an important role in the dissolution of sintered specimens.With the same sample, however, the dissolution rate decreased as the sintering temperature increased.For example, the rate of dissolution of the sintered specimen, which was prepared by sintering an apatite sample initially containing about 12wt% carbonate at 750℃, was nearly one-fifth that of the non-sintered specimen and about one-third that of a non-sintered specimen of deproteinated bone.Comparison of carbonate apatite sintered at 750℃ and a carbonate-free apatite sintered at 1, 200℃ showed that the dissolution rate of the former was approximately four times as great as that of the latter.This finding clearly suggests that the sintered carbonate apatite is much more soluble than sintered carbonate-free apatite, indicating that carbonate apatite is more useful as a bone substitute material.
